Abstract: Oscillation modes are often treated as linear perturbations to the background star or planet.  However, in some systems the mode amplitudes are so large that the linear approximation is no longer valid and nonlinear effects must be considered.  In this talk, I will discuss two systems where nonlinear effects can be significant: tides in hot Jupiters and solar-like oscillations in red giants.  In hot Jupiter systems, nonlinear mode interactions can greatly enhance the rate of tidal dissipation and significantly impact the planet’s formation and orbital evolution.  In red giants, stochastically excited mixed modes are unstable to nonlinear interactions over a broad range of stellar mass and evolutionary state.  By solving the dynamics of large networks of coupled modes, I will show that nonlinear damping can substantially suppress the energies of gravity-dominated mixed modes.  Asteroseismic measurements may therefore need to consider nonlinear mode dynamics when interpreting the observed amplitudes and frequencies of modes, especially in more evolved red giants.

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https://aarhusuniversity.zoom.us/j/65974972623?pwd=a3V6Tmx3V1NqTEdhWmRySVp1Y3RxQT09

Meeting ID: 659 7497 2623

Passcode: SAC2021Sem